Introduction Dizziness is a common complaint presented in the emergency department (ED). A subset of these patients will present with acute vestibular syndrome (AVS). AVS is a clinical syndrome defined by the presence of vertigo, nystagmus, head motion intolerance, ataxia, and nausea/vomiting. These symptoms are most often due to benign vestibular neuritis; however, they can be a sign of a dangerous central cause, i.e., vertebrobasilar stroke. The Head Impulse test, Nystagmus, Test of Skew (HINTS) examination has been proposed as a bedside test for frontline clinicians to rule out stroke in those presenting with AVS. Our objective was to assess the diagnostic accuracy of the HINTS examination to rule out a central cause of vertigo in an adult population presenting to the ED with AVS. Our aim was to assess the diagnostic accuracy when performed by emergency physicians versus neurologists. Methods We searched PubMed, Medline, Embase, the Cochrane database, and relevant conference abstracts from 2009 to September 2019 and performed hand searches. No restrictions for language or study type were imposed. Prospective studies with patients presenting with AVS using criterion standard of computed tomography and/or magnetic resonance imaging were selected for review. Two independent reviewers extracted data from relevant studies. Studies were combined if low clinical and statistical heterogeneity was present. Study quality was assessed using the QUADAS‐2 tool. Random effects meta‐analysis was performed using RevMan 5 and SAS 9.3. Results A total of five studies with 617 participants met the inclusion criteria. The mean (±SD) study length was 5.3 (±3.3) years. Prevalence of vertebrobasilar stroke ranged 9.3% to 44% (mean ± SD = 39.1% ± 17.1%). The most common diagnoses were vertebrobasilar stroke (mean ± SD = 34.8% ± 17.1%), peripheral cause (mean ± SD = 30.9% ± 16%), and intracerebral hemorrhage (mean ± SD = 2.2% ± 0.5%). The HINTS examination, when performed by neurologists, had a sensitivity of 96.7% (95% CI = 93.1% to 98.5%, I2 = 0%) and specificity of 94.8% (95% CI = 91% to 97.1%, I2 = 0%). When performed by a cohort of physicians including both emergency physicians (board certified) and neurologists (fellowship trained in neurootology or vascular neurology) the sensitivity was 83% (95% CI = 63% to 95%) and specificity was 44% (95% CI = 36% to 51%). Conclusions The HINTS examination, when used in isolation by emergency physicians, has not been shown to be sufficiently accurate to rule out a stroke in those presenting with AVS.

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The conducting polymer polyaniline (PANI) has been considered to be a promising pseudocapacitive electrode material for supercapacitors due to its high specific capacitance, low cost, and environmental friendliness. However, the poor cycling stability of PANI during the charge–discharge processes limits its widespread practical application. Herein, a facile synthetic method is demonstrated for covalently grafting an aniline tetramer (TANI), the basic building block of PANI, onto 3D graphene networks via perfluorophenylazide coupling chemistry to create a hybrid electrode material for ultralong‐life supercapacitors. The design, which substitutes long‐chain PANI with short‐chain TANI and introduces covalent linkages between TANI and 3D graphene, greatly enhances the charge–discharge cycling stability of PANI‐based supercapacitors. The electrode material, as well as the fabricated symmetric all‐solid‐state supercapacitors, exhibit extraordinary long cycle life (>85% capacitance retention after 30 000 charge–discharge cycles). The capacitance can be further boosted through fast and reversible redox reactions on the electrode surface using a redox‐active electrolyte while maintaining outstanding cycling stability (82% capacitance retention after 100 000 cycles for a symmetric all‐solid‐state device). While conducting polymers are known to be limited by their poor cycling stability, this work provides an effective strategy to achieve enhanced cycle life for conducting polymer‐based energy storage devices.

Supercapacitors are energy storage and conversion devices that display high power.